Good follow up letter

[Toni]

I am trying to find a resource of how to white a good follow up letter.
What should I say that would convince the employer that I am serious and I liked the company and the interview?

[Bronco]

There are quite a few threads here about follow up letters, give those a read first.
The important thing to remember is not to sound desperate or needy.

Simply thank them for the interview, and reiterate again how much you would love to work for their company and WHY (eg it fits perfectly into your career plan etc).

[Toni]

Thanks for the tips.

Someting like:
Thank you for the opportunity; it was nice meeting you; I am really impressed by your company; I hope I can contribute....

[lookingforjob]

Thanks them for the interview and let them know that you really like the position and the company and you'll be more than happy to work for them...

[Tim]

Thanks for the tips.

Someting like:
Thank you for the opportunity; it was nice meeting you; I am really impressed by your company; I hope I can contribute....

Thats about right
Of course, formatting it nicely with correct grammar and spelling will also go a long way :)